Report on Turrialba (Costa Rica) — 10 June-16 June 2009
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 10 June-16 June 2009
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2009. Report on Turrialba (Costa Rica). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 10 June-16 June 2009. Smithsonian Institution and US Geological Survey.
10.025°N, 83.767°W; summit elev. 3340 m
All times are local (unless otherwise noted)
On 14 June, OVSICORI-UNA reported that fumarolic activity from Turrialba had been observed all around the upper flanks of the active W crater. During the previous two months, the fumarolic activity was accompanied by widening of radial cracks (1.5 cm on average), 1-2 km tall gas-and-vapor plumes, and one sustained discrete seismic swarm. Temperatures of fumarolic vents in the lower parts of the crater were between 120 and 160 degrees Celsius. The temperature of summit cracks was 94 degrees Celsius. Dairy pastures and forests had been burned as far away as 3.5 km NW and W.
Geologic Background. Turrialba, the easternmost of Costa Rica's Holocene volcanoes, is a large vegetated basaltic-to-dacitic stratovolcano located across a broad saddle NE of Irazú volcano overlooking the city of Cartago. The massive edifice covers an area of 500 km2. Three well-defined craters occur at the upper SW end of a broad 800 x 2200 m summit depression that is breached to the NE. Most activity originated from the summit vent complex, but two pyroclastic cones are located on the SW flank. Five major explosive eruptions have occurred during the past 3500 years. A series of explosive eruptions during the 19th century were sometimes accompanied by pyroclastic flows. Fumarolic activity continues at the central and SW summit craters.